The shooting happened about 12:20 p.m. at the campus at 2700 W. W. Thorne, near Aldine Westfield, according to the Harris County Sheriff's Office.

Two people were wounded, one of them critically, officials said. The condition of the other victim was not released.

Officials said two gunmen appeared to have been involved in the shooting. One of them was taken into custody a short time later. The other man is on the run.

Law enforcement officials were searching the area near the campus, using tracking dogs. The Houston police SWAT team is also on campus.

Investigators are still trying to determine what sparked the gunfire.

"We know that shots have been fired and we are in a shelter-in-place situation on the campus," said Vicki Cassidy, manager of media relations for Lone Star College System. "It's a pretty chaotic scene at this point in time."

Cassidy said she could not provide any other details about the shooting. The campus is one of six that makes up the community college system.

Early reports indicate the shooting may have occurred in the library as well in the cafeteria.

The campus has been placed on lockdown as authorities investigate the case. Lone Star posted an alert message on its website at 12:52 p.m. that the North Harris campus was locked down.

"Students, Faculty and Staff are advised to take immediate shelter where you are. Do not enter the campus until notified further," the message said.

Officials also asked other people not to come to the campus.

Laura Sanchez came to Lone Star to pick up her brother. She arrived at the campus about 12:45 p.m.to pick up her brother but she couldn't get close enough to do so.

"There were like a whole bunch of people," she said. "I turned around and went back home and called my dad.''

Sanchez said her brother had planned to go to the college library. She said a friend told her on Facebook that the shooting was in the college cafeteria and that if her brother was in the library, he should be OK.

Four Aldine ISD schools have been placed on lockdown as a precaution: Parker Intermediate, Dunn Elementary, Nimitz High School and Nimitz ninth-grade campus.

College student posted on the twitter accounts that shots were fired. A person named Amanda tweeted she was in her classroom in the Academic Building when she heard gunfire in the hallway. There were more shots, rapid shots in the hallway, the person tweeted.

A person referred to as Sunkissed Johnson reported on Twitter of being in the library and hearing shots fired. Later he said he was evacuated and said he was safe.

The nearby Woodcreek subdivision was put on alert by its property owner's association.

"DO NOT go to the college. Shots have been fired at 1:08pm. One gunman is on the loose. REMAIN IN YOUR HOMES!! DO NOT attempt to drive down W.W. Thorne in either direction." the message said.